Apologies for the late reply on this but have been off on a little vacay/travel.
I've not made a decision on whether to offer this option yet for the simple reason I've no idea of the demand. I also have a 2x4HD that I use in my main personal rig and I do want to test this out. I'm sure it will work just fine but have yet to do it.
This 4 channel arrangement would essentially be the same internally as our LDR1B.V25 which is a 4 channel balanced attenuator. The rear panel would have to accommodate 4 RCA inputs and 4 RCA outputs which is doable with current enclosure form factor and available panel real estate but would need a new rear panel design. Could not handle a balanced version within current enclosure becasue it would require 8 internal channels (twice the boards/hardware etc.) which simply would not fit.
As someone pointed out, if you're willing to go DIY your could adapt our LDR1B.V25K balanced preamp kit with a different custom rear panel that you'd have to source yourself plus RCA jacks. If you're willing to accept a bare aluminum 4 channel RCA rear panel (no brushing, anodizing or labels) I could fabricate one for a $100 adder.
Thanks for the reply Morten,
No apology needed, hope you got some rest.
Re enclosure: would purchase preamp in kit form and supply my own enclosure and assemble myself, more than likely a rack enclosure as its going in a rack, doesn't have to look pretty, but neat and tidy would be nice and most importantly it has to work.
What you propose could work. However it would be going into a 5.2 channel system, so I would still need an extra input(L+R) from the surround processor, so potentially a 2nd V25 board.
However correct me if I'm wrong, from what I can see the V25 board has 4 outputs(2 pairs)? If you could have minimum 3 inputs(or as many inputs as you care to offer), input 1(lets say used for sub channels from 2x4HD) is 'assigned' to output 1 and is always 'on'. Then input 2 and 3(or other inputs) are switchable to output 2. For level volume control everytime you switch between inputs 2 and 3(or others) the volume automatically goes to 35(or 50% as talked about in this thread....http://www.audiocircle.com/index.php?topic=120337.0
) on ALL inputs, which is what I think already happens? and then to get the 'HT bypass' affect you have to(using the remote) put the volume upto full?
Is that possible? If you need a little diagram let me know.